Jury Expected to Get Slaying Case : Trial: The defendant is accused of strangling his former wife with piano wire. He faces the death penalty.

A San Fernando Superior Court jury must try to decide whether an abusive, convicted child molester strangled his ex-wife while an accomplice brutally raped her, or whether he merely was the most convenient suspect because of his past.

The jury is expected to begin deliberating today the fate of William Edward Stevens, 50, of Sylmar, who faces the death penalty.

Stevens is charged with the Feb. 9, 1990, murder of his ex-wife, Rufina Stevens, 47, whose mangled, nude body had been placed face down on railroad tracks near her Sun Valley home and then hit by a freight train.

Both sides in the case acknowledge that Stevens--who served a jail term for molesting the youngest of his two daughters and later two separate prison terms for violating parole--had assaulted the victim in the past. He also had told his daughter that he had thought about killing his ex-wife, although never seriously.

Both sides also acknowledge that there is no physical evidence directly linking Stevens to the slaying. DNA evidence found on the body does not match Stevens, nor do footprint castings taken at the scene. There were no witnesses to the slaying.

But there is little agreement about much else involving the case.

Deputy Dist. Atty. Jeff Jonas argued Monday in closing statements that Stevens killed his ex-wife because “he knew he had lost ultimate control over her.” Stevens has maintained his innocence, claiming that he was home asleep at the time of the slaying.

Jonas said Stevens thought he had planned the perfect crime by disguising his involvement in the slaying, making sure no prints were left behind, and that someone else’s semen would be found on her body.

The prosecutor argued that Stevens purposely used a piano wire to strangle his ex-wife, knowing it could not be traced like a gun or a knife. Police found three wires missing from a piano in the house in which Stevens rented a room.

But Jonas told the six-man, six-woman jury that Stevens botched his perfect crime by indirectly “confessing” several times through “Freudian slips” in statements to the police and in his testimony in court.

Jonas said that Stevens knew information that only the killer could have known, such as the fact that the woman had been strangled before being hit by the train. Stevens also acknowledged to police that he once said that if he was to kill his ex-wife he would use a piano wire.

But Stevens’ attorneys, Patrick Atkinson and Vivien McGuire, contend that Jonas “overstated and exaggerated” Stevens’ statements, and that prosecutors are using his past to try to pin the slaying on him.

Stevens’ past “has no relevance to this case,” said Atkinson, who is scheduled to complete his closing arguments today.

“Mr. Jonas wants you to dislike and hate Bill Stevens. It will be easier for you to convict him if you hate him.”

During the two-month trial, a jail informant testified that Stevens told him while both were awaiting court appearances that he killed his wife. However, McGuire argued that the informant pieced together information to give prosecutors to avoid prison, where he expected to be killed for informing on other prisoners.

The defense also produced a private pathologist who testified that Rufina Stevens’ neck wounds could not have been caused by a piano wire, but rather by a smaller instrument such as a wire survival saw.

A neighbor of Rufina Stevens testified that on the day of the slaying she had left a wire saw with a transient living in a trailer on her property so that he could cut some tiles for her. The woman, Frances Santos, said she saw the man early the next morning and he “looked frightened to death.”

Santos testified that her wire saw was missing, and that she has not seen the transient since that day.